Traffic congestion is a serious problem in urban areas of many countries due to the increasing amount of vehicles on surface streets and accompanies fuel-wasting and air-pollution. This problem can be alleviated by adopting a ride-sharing service. The main idea of ride-sharing service is to collect travelers whose travel destinations are nearby into one vehicle. In doing so, we can reduce the amount of vehicles on surface streets and meantime save fuel. In this paper, we focus on the taxi-sharing service and propose a dynamic taxi-sharing system based on Intelligent Transportation Systems (ITS) technology. In the proposed system, we can immediately serve each irregular ride-sharing request and find a fuel-saving taxi for it. The simulation results show that our solution can exactly select a fuel-saving taxi for each ride-sharing request and outperform in responding time, the number of compared taxis, and fuel-saving while comparing with existing solutions.